YASKAWA VS-505WII User manual

Varispeed-50 1 )W11
INDUSTRIAL USETHYRISTOR
CONVERTER UNITS
Before initial operation, read these
instructions thoroughly, and retain for future reference .

When properly installed, operated and maintained, this
unit will provide a lifetime of optimum operation . It is
mandatory that the person who operates, inspects,
and
maintains this equipment thoroughly reads
and
understands this manual and has in his possession
at
all time .
IMPORTANT
. Make no
withstand voltage test on the VS-505WII
because
it incorporates semi-conductor
electronic
circuits .
. If insulation resistance tests are
neccessary, make
them only in accordance
with the instructions given in
this manual
.
682-215
Type CDMR-W11

Type CDMR-WIL
(Type S)

(Type
L)
460 V, 105 A

460 V, 420 A
CONTENTS
682-234
.
Do
not tamper with potentiometers of the power units
since they were preset
at the factory
before
shipment .
Varispeed-505W11 (VS-505WII) is a thyristor
converter
unit for varispeed reversible operation of industrial
DC
motors .
For correct operation of VS-505WII,
users must
thoroughly read these instructions .
This manual is also
necessary for maintenance and troubleshooting,
and
threfore should be kept filed for ready reference
.
For details on DC motors,
refer to "Instructions for
Industrial DC Motors" (TOE-C435-3B) .
Type CDMR-W11
(Type
M)
230 V, 260 A
682-227
RECEIVING . . . . . . . . . . . . 3
Interconnections . . . . . . . . . . . 4 MAINTENANCE . . . . . . . . 10
STORAGE . . . . . . . . . . . . . . 3
Cautions when Wiring . . . . . . 4
Periodic Inspection
. . . . . . .
10
LOCATION . . . . . . . . . . . . . 3
TEST RUN . . . . . . . . . . . . . . 5
Parts Replacement . . . . . . . 10
INSTALLATION . . . . . . . . . 3Check
before Test
Cautions in Replacing
WIRING . . . . . . . . . . . . . . . . 3 Run
.. . . . . .
. . . . . . . . . . . . . 5
Control Board . . . . . . . . . . . 14
Component Arrangement
No-Load Operation . . . . . . . . 6
Troubleshooting Guide ..
. .
14
in VS-505WH . . . . . . . . . . . . 3
Full-Load Operation
. . . . - 6
SPAREPARTS . . . . . . . . . . 15
Terminal
Sizes and
Carrying Currents . . . . . . . . . 4 Adjustment
. . . . . . . . . . .
. . . 6
REFERENCE . . . . . . . . . . . . 16

RECEIVING
or missing .
STORAGE
If the equipment is temporarily stored
or ma-
chine stops for an extended length of time, the
following precautions
should be taken .
LOCATION
Store the equipment under
the following condi-
tions .
"
Free from rainfall and drops of water
" Clean and dry
(a)
Control Circuit
" Free from corrosive gas and
liquid
" Ambient temperature : OOC to 40 0 C
WIRII4G
Make wiring in reference to the interconnection
diagram furnished on your order and the follow-
ing .
COMPONENT
ARRANGEMENT IN
VS-505 W II
Figs
.
1 to 3 show component arrangement in
the VS-505WII .
NAMEPLATE
"CAUTIONS
I NOPERA-
TION"
CONTROL
SUPPLY
VOLTAGE
SELECTOR
TAP
POWER CIRCUIT
BOARD (2PCB)
(a)
Control
Circuit
Fig . 1 Type CDMR-WI[, -S, (460 V, 115 A)
(b) Main Circuit
CONTROL CIRCUIT
BOARD (1PCB)

THYRISTOR
CONNECTOR

POWER CIRCUIT
COOLING
BOARD (2PCB)

FAN
MAIN CIRCUIT
EXTERNAL
TERMINAL
(b) Main
Circuit
Fig .
2 Type CDMR-WII, -1V[ (230 V, 260 A)
THYRISTOR
PROTECTIVE
FUSE
(2 FOR 220 V
CLASS, 3 FOR
440 VCLASS)
THYRISTOR
PROTECTIVE
FUSE
(2 FOR
220 V
CLASS, 3 FOR
440 V CLASS)
The equipment has been put through severe
tests at the factory before
shipped . After un-
packing, however, check and see the following .
"
Less
vibration
INSTALLATION
" Its nameplate data meets your requirements .
" It has sustained no damage while in transit .
Select .a location described in STORAGE and in-
" Fastening
bolts
and screws are not
loosened .
stall the equipment
by proper procedure in keep-
" Devices built in the cabinet are not damaged
ing the equipment in good working condition .

WIRING
(Cont'd)
4
TERMINAL SIZES AND CARRYING
CURRENTS
Table 1 shows
the size and the current earring capacities
of the terminals of
VS-505WII . Select leads with
sufficient
current carrying capacity . Refer to "Cautions
when Wiring" .
Table 1 Terminal Size and Current Capacity
Notes
- Terminal size other than listed above is M4 and
current capacity
is
2 A or below .
Rule of thumb of AC main circuit power capacity
1 .2XF XEXI (VA)
E :

Supply voltage
I:

AC main circuit current
SURGE
ABSORBERS
Control
Circuit

(b) Power Circuit
Fig . 3 Type
CDMR-WII :, -L (460 V, 420 A)
INTERCONNECTIONS
Make
connections of VS-505WII with
associate
units according to the
interconnection diagram
separately
furnished .
CAUTIONS WHEN WIRING
Main
Circuits
Use 600 V PVC
insulated wires or
cabtyre cables
with the current
carrying capacities of the com-
bined DC motor
for AC main
circuit terminals
(U, V, W) and DC
main circuit terminals (P,
N) .
Field
Circuits
Signal
Circuits
MAIN CIRCUIT
EXTERNAL TERMINALS
Use
600 V PVC insulated wires or
cabtyre cables
with the current carrying capacities
of the com-
bined DC
motor for field power circuit terminals
(Uo,
W o, U 1 ,
Wl)
and field circuit
terminals (J,
K) .

Use stranded wires
of cross-section 5.5
mm 2 or larger for field
circuit terminals (J, K) .
Use shielded
wires or twisted wires of twisting
pitches 20 mm or
smaller for
the
speed setting
circuit
terminals (6 to 10) , speed feedback ter-
minals
(2, 3),
tachometer circuit terminals (50 to
52) .
Fig . 4 Pitch of Twisted Wire
AC
Main DC Main Field
CDMR-W11
Circuit Circuit Circuit
Car- Car- Car-
RatedRated
Ter
- ryingTer- ryingTer-rying
Volt- Out-
minal Cur- minal Cur-
minal Cur-
age
e put
rent Size rent Size rent
V kW
A A
A
25 M4 21 M
5 25
35 M8 29 M8 35
45 M8 37 M8
45 M4 12
90
M8 74 M8 90
230 105 M8
86 M8 105
180 M10 147 M10 180
M4
22
260
M10 213 M10 260
420 M12 343 M12
420
M4
25
550 -M12
449 M12 .550
50 M8 41 M8
50
90 M8
74 M8
90
M4 12
105 M8 8 'M8 105
460 180 M10
147 M10 180
M4
22
260 M10 213 M10 2&0
420
M12 343 M12 420
M4 25
550 M12 449 M12
550

Separation of Signal Cables from Main
Circuit Cables
To avoid inductive
interference from other cables,
run the shieldedor twisted wires
(1
to
55)
separatefrommain circuit cables ( U , V, W ;
U o ,
WO ;
U1,
W 1 ; P, N ; J, K) in a bundle or thru a duct .
CAUTION
After
wiring,
check interconnections . Make in-
sulation resistance tests using a 500 V megger .
Connect VS-505WIE main circuit terminals (U, V,
W ;

U o, W
o ;

U1,
W 1
;
P,
N ; J, K) with
common
lead . Measure the insulation resistance between
common lead and the ground . When the test
result is 2MSZ or more, it means that wiring is
good .
TEST RUN
When the VS-505WIL has been correctly installed
and wired, the unit shall be tested through a
test run as follows .
If trouble is foundduring the test run, re-
fer to "Check Before Test Run" and "Trouble-
shooting Guide" for necessary measures . If the
cause of the trouble cannot
be
located, or repair
is impossible, notify our service station, giving
the details of trouble conditions .
CHECK BEFORE TEST RUN
Make the following checks prior to the test run .
Table 2 Check before Test Run
* VS-
505WE
of
larger
capacity than
230
V,
45 A or 460 V , 90
A are provided with a thyristor cooling fan .
Fig
. 5 Inspection
Window of DC Motor
D
Fig . 6 Tap Selection of Control
Supply Voltage
Table 3 Supply Voltage Allowable Range
50H z
60Hz
For
50 Hz,
slide
the switch
key up .
For 60 Hz, slide
the switch key down .
Fig . 7 Power Frequency
Selector Switch
Check Pomts Check Items
Interconnec- " Correct wiring
tions between " Tightening of terminal screws
v s- 505WE
and Associ-
ate Units
DC Motor " Disconnection from the driven machine
" Removal of thrust block
" Remove inspection covers and blow out with
air to clean commutator . (Fig . 5)
VS-505WII " Adhesion of dirt or dust on the enclosure
" Smooth hand
rotation
of thyristor cooling
fan
" Check items
in "Cautions
in
Operation"
on
the back of the control board door
"
Correct connection of the shunt connector
to the voltage selecting tap (Fig .
6)
" Correct setting of the frequency selector
switch (Fig . 7)
" Correct adjustment of potentiometers on the
control board (1PCB) Refer to red paint
Supply Volt- " Voltages of anytwo of phases U, V, W are
age at Input within the values on Table 3 . Check with a
Terminals of tester .
VS-505WR " Terminals
Uo
and U 1 , and W o and W, are
connected .
" Rotating direction of the motor blower meets
with the arrow marked on the
blower .
Nominal
Supply
Permissible Voltage
Supply
Frequency
Voltage Selector
Voltage Variation
Tap
200 V
50/60 Hz 170
-
220
V 200 V
220
V 50/60 Hz 187 - 242 V 220
V
400 V 50/60 Hz
340 - 440 V 400 V
440
V 50/60 Hz
374 - 484 V 440 V

TEST
RUN

(Cont'd
)
NO-LOAD OPERATION
After making the checks specified before test
run,
thoroughly check the environment of the system for
safety .
Check the polarity of DC tachometer generator
feedback voltage . When the motor is running forward,
the polarity of VS-505WIl signal terminal 2 (3 :

0 V) is
minus and it
is plus during reverse running of the motor .
Then, run the motor without load according to
Table 4 .
FULL-LOAD
OPERATION
Before starting full-load operation, stop the power
supply, couple the DC motor to the driven machine, and
check the motor and the driven machine for safe and
obstruction-free conditions . Table 5 gives full-load
operation procedure .
Table 4 No-load Operation
* VS-505W11 . rated 220
V . 45 A and above and460 V . 90 A and above are
provided with a
thyrlstor cooling fan .
6
ADJUSTMENT
Do not tamper unnecessarily with the potentiometers on
the control circuit board since they have been adjusted
at the factory before shipped .
Adjuster
Locations and Functions
Adjuster locations on the control
circuit board and
functions
are shown in rig . 8 and Table 6 .
The
characteristics of control circuit board check
terminals
are shown in :Fig . 9 and Table 7 .
0
sx
V
~
0
Fig . 8 Adjuster Locations on
Control
Circuit Board
'fable 5 Full-load Operation
Order Operation Check Items
9
1
Set the speed reference
at zero .
2 Turn on main circuit Smooth rotation of the
powersuppy . thyristor cooling fan .
Smooth rotation of the
blower for DC motor .
Rotating direction of the
blower
meets with the mark-
ing on the blower .
3 Make an operationalse- Indication light "PREP" on
quence and check to be the control board(1PCB)
sure that operation is turns on .
ready . (Turn
on ready
signal, motor
cooling
fan
ON /OFF signal .)
4
Turn-on the operation
signal .
5 Gradually, increasethe Smooth acceleration of DC
speed setting value . motor .
No abnormalodor, smoke,
vibration and noise on DC
motor .
6Remove
the hand-hole No brush chattering and
cover and check the
I
sparking at thebrushes .
commutator .
To avoid excessive temperature rise of DC motor
winding in frame 112, 132, reclose the window
within 5 minutes .
7 Gradually,turn the Smooth
acceleration of
DC
speed setting potentiom- motor .
eter clockwise .
8
' Increase the speed
set-
DC
motor rotates at the
ting value to the maxi- maximum
speed
. Check
mum . with a speedometer
.
9 Change the
speed to DC motorspeed corre-
various values
. sponds with the set values .
10 Turn off the
operation
DC
motor suddenly
stops .
signal .
11 Turn off the
main cir-
cult power supply .
Order Operation
1 Se t the speed at zero .
2 Turn o n th e main circ
u it power supply .
3 Turn on operation signal and gradually
increase the speed .
Check to be sure
that the motor and driven machine are
correctly r
u nning .
4 Tu rn off the ope r ati on sig n
al .
5 Tu rn of f ma i n circuit power supply .

Table 6 Control Circuit Board
Adjuster Locations and Functions
Type : o Adjuster Adjuster
Adjuster Function Adjusting Method Specifications
Adjusters
Location
Name
1 ~+
RATE
Accel time adjustment at fwdrun .
Clockwise rotation increases 3 - 75 sec
(Decel time adjustment at rvs run .)
accel time .
2
(D
RATE
Decel
time adjustment at fwd run
Clockwise rotation increases
decel time .
3-75
sec
(Accel
time adjus tment at rvs run .)
3 NGAIN
ASR
Gain adjustment .
Clockwise rotation increases GAIN
4
Speed
feedback adjustment . Clockwise rotation decreases
± 6 V/10046 specA
NMAX
s " geed .
5 IGAIN
ACR Gain adjustment . Clockwise rotation increases
gain .
6
Main circuit current feedback Clockwise rotation decreases +3 V/100% current
IFB
adjustment .
current .
7
F LIMIT
Speed and current limit value at
Clockwise rotation increases 150% (Standard)
forward run . limit value .
8 R LIMIT
Speed and current limit value
at Clockwise rotation increases 150% (Standard)
reverse run . li mit v alue .
9 CEMF
Counter electromotive force Clockwise rotation increases 0 . 17 - 0 .84 times
Potenti-
compensation . gain .
ometers
10
SM
Speedometer adjustment . Clockwise rotation increases 1 mADC max
.pointer swin : .
Ammeter adjustment .
Clockwise rotation increases pointer 1
mADC max
11 AM
swing .
12 NOFS ASR offset adjustment
.
evolt .i z- e
13 IOFS ACR offset adjustment .
t-volta ,", .-e
14 KIPP
Phase shift lag limit adjust- Clockwise
rotation advances shift lag
155oek Standard
ment limit
Adjustment of phase shifter Clockwise rotation advances 90'-k -
li_T1i°eZ
15
PSB
operation point . : , hase . (Adjustable)
Setting overload detection Clockwise rotation increases 110% Standard
16 OL% start point . overload detection start
. , oin t .
17
OLT
Setting overload detection Clockwise rotation increases 150%, 6 .0 sec (Standard)
time .
o .eration
time .
18 ZCD
Setting zero
current detec-
Clockwise
rotation
increases 0% - 10n (Adjustable)
tion level .
detection
level .
7%
(Standard)
19 IREF
Setting field
current
. Clockwise rotation
increases
field current .
Resistor
20
14FBR
1FBR - Rough adjustment of field cur-
Selection
rent detection voltage level .
Open
the
resistor according Refer to motor specifi-
(Open)
21
5FBR - Rough adjustment of main circuit to specifications
. cations .
9FBR current detection voltage level .
Slide 22 1SW
Control Method selector (Speed N-1 Current
Switch
control) control)
~ M®
50 Hz- " 0 Hz
Rough adjustment of speed Selection o the voltage level
24
A -
D detection voltage level . according to type
of tack-gen
and motor rated s . ,
eed .
25
E
Selection of soft start El
operation
E2
Soft start
Selection of PI or P control by ©
PI
control
26
F
ACR control method
"A
P contr ol
Selection of PI or P control by © Pc mntrol
Plug
27
H
ASR control method ©
P1 control control
Selection
Selection of zero-speed condi- J 1 block after motor
28 tion at
motor overheat . reached
zero speed by
J
stop o .eration .
~~ ime(giate gate block .
29
K
Selection of start interlock ©Wit
zero-speed condition . ~~ Without
Selection of zero-speed cord-
Field half-reduced after
tion at motor blower stop . ttiotor zero-speed by
stop
30 L
_operation . (Gate block)
Field half-reduced immediately .
-
(Gate block)
Selection of exciter according I©Exciter used .
31 M
to typeof motor field . © Exciter not used .
Open "
Speed control by
voltage detection .
" Speed control by AC
Short-
32 OPN
tach-gen .
circuit Short -
Jumper circuited
other than the above .
Open
-
Special
application .
33 OPS --
Short-
Other than the above .
circuited

TEST
RUN (Cont'd)

Adjustment Procedure
Fig . 9 Control
Circuit Check Terminals
N MAX (Speed feedback adjustment)
Table 7 Control
Board Check Terminals
To adjust the DC
motor speed exactly to the
reference speed, proceed as follows .
1 . Prepare the
tachometer having the required
accuracy .
2 . Operate the
DC motor at no load (or
less
variation)
.
3 . Measure the
speed reference voltage
with a
voltmeter . Correct the
voltage to that of desired
motor speed .
4 . Measure the motor
speed with a tachometer
.
5 .
If the speed does not
reach the desired speed,
turn NMAX counterclockwise
to increase the
speed .
Signal Name
Check
Terminals
Normal Value
CH22 OV (SG )
Stable
power supply
CH24 +15 V
CH25 -15 V
CH19 +24 V
CH20 -24 V
Allowable voltage
Unstable power supply
CH23
+24
V (Pulse amplifier
supply)
function range :
±20%
CH4 :6 V/100%
com mand (8 Forward, (+
Reverse)
Speed reference
CH5 ±6 V/100%
com mand ((D Forward,
(DReverse)
Speed feedback
CH3
;6 V / 100% spe ed
(0
Forward,
+
Reverse)
Forward CH9
Current command
Reverse
CH8
-3
V/100% command
Current limit
Forward
CH7 +3 V/100% current limit
(Speed limit)
Reverse CH6
(+6
V/100% speed limit)
Main Current
feedback
CH18 +3 VI100%
current
Circuit
Power
Current limiter output
CH2
. -1 V at gate
ock bl
Approx
0 t o
+6 V when controlling
Phase shifter input
CH16
Approx . +5 .5 V at 60 Hz,
+6
.5 V at 50 Hz at gate
block .
+1 to +5
.5 V at 60 Hz,
+1 to +6
.5 V at 50 Hz
when controlling .
Counter
electromotive force input
CH1 0 - ±5 V
Overload
detection start point
CH21 110% (Approx : -1 .65
V)
Zero-current detection
CH15
0
V
at load current conduction, approx .
+12 V at
0 A of load current .
Pulse
amplifier power Forward
C1112
0
V at reverse opera-
tion .
Approx
.
+24 V at forward
operation .
supply
Reverse
CH13
0 V at
fozwaz~d opera-
tion .
Approx . +24 V at
reverse
operation .
Gate block (at failure)
CH14 0
V normal, : !pprox . -12 V at gate bloc
k .
u Uu
Phase shifter
synchronization v
4/_~s
ar
U, V, W : Main circuit
power supply
w
w
11 y
input power supply .
Current command
CH11
Voltage according
to ~ -6 V/5 A
Field
Current
feedback
CH17
field current .
+3 V/5 A
Power Phase
shifter input
CH10
Approx . +5
V at 60 Hz,
+6 V at 50
Hz at field
block .
+1 to +5
V at 60 Hz,
+1 to +6
V
at 50 Hz
when controlling
.

6 . If the speed exceeds the desired speed, turn
NMAX
clockwise to decrease
the speed .
FLIMIT (Forward limit value adjustment)
RLIMIT (Reverse limit value adjustment)
1 . Current limitation (Speed control)
Slide the control method selector switch (1SW) on
the control circuit board to N . When the voltages
at CH7 (forward)
and CH6 (reverse) are +3 V,
100% current limit value is obtained
. Current limit
value can be set within the range of 0% to 250%
by
F LIMIT and R LIMIT .
2 . Speed limitation (Current control)
Slide
the control method selector switch (1SW)
on
the control circuit board to I . When the voltages
at CH 7 (forward)
and
CH 6 (reverse) are +6 V,
100% speed limit value is obtained . Speed limit
value can be set within the range of 0% to 250%
by F LIMIT and R LIMIT .
PSB (Phase shifter operating point adjustment)
PSB sets the phase shifter operating point .
1 . When the current controller (ACR) is inte-
gral-controlled
Connect the
plug
selector F on the control
circuit
board at Fl . Turn PSB fully counterclockwise .
2 . When the current controller (ACR) is ratio-
controlled
Connect the plug selector F on the control circuit
board at F2 . Turn PSB clockwise gradually with
reference current at 0 V (0 V at CH 2) , and set
at the position
where main circuit current
is
ready to start .
CEMF (Counter electromotive force compensation)
Current loop is vulnerable
to
counter
electro-
motive force . In order to obtain optimum per-
formance, a compensating electromotive
force has
to be biased on the phase shifter, depending on
the control mode .
1 .
When the current controller (ACR) is ratio-
controlled
Adjust CEMF,
observing the motor acceleration
current with a synchroscope . Turn CEMF fully
counterclockwise, and turn CEMF clockwise
gradually until optimum value shown in Fig . 10
is
obtained .
2 . When the current controller
(ACR)
is inte-
gral-controlled
MOTOR
ACCELERATION
CUR 1tENT
Field Current Adjustment
Fig .
10 CEMF
Adjustment
CEMF compensation reduces the loss
time due to
Forward/Reverse selection to as the same level
as
the
integral control
of ACR . Turn CEMF fully
counterclockwise, and during motor acceleration
by current limit gradually turn it clockwise until
the voltage at CH2 on the control
circuit board
stabilizes .
Field current adjustment
is required for
checking
the setting
at the factory or for fine
adjustment .
To change
the setting, selection of
resistors (1FB R to
4FB R) on
the control circuit board
is required .
1 . For constant
field current
a .
Connect a DC ammeter
to the field circuit .
b . Adjust
so that the ammeter indicates the
rated field
current with IREF on the control
circuit board . (Refer to the
test report or
nameplate
data .)
2 . For
field weakening control
SYNCHROSCOPESCREEN
ADJUST THE SWEEP SPEED
ADAPTED TO THE MOTOR
ACCELERAITON TIME TO
BRING THE CURVES TO A
CONVENIENT POSITION .
Field weakening control is made for the VS-505WII
combined
with
field weakening control unit type
JGSM-51-
D .
a . Connect DC ammeter to the field circuit and
DC voltmeter to output terminals P, N .
b . Turn IREF on the control circuit
board and
FORCE
FLD andV LIMIT of field controller
fully counterclockwise .
c . Seat the minimum field weakening current
by
IREF . In this case, set the current at 80% field
weakening current at maximum speed
. (See the
test report .)
d . Set the rated field current (field intensifying
by FORCE FLD .

(See the test report
or name-
plate data .)
e . Alter the motor
starts, gradual increasing
the speed reference increases the voltage
across
P and N and governs it at some value .

Turn V
LIMIT clockwise gradually so
that the governed
value is the rated voltage .

MAINTENANCE
VS-505WIl requires almost
no daily inspection .
To keep the correct
and successful operation,
periodic
maintenance operations should be
per-
formed . The users should prepare
their own
maintenance programs based on the following
guidelines
.
PERIODICINSPECTION
Table 8 shows the minimum
inspection items and
the procedures
.
Table 8
Periodic Inspection
PARTS REPLACEMENT
. Replace the parts
required after
checking the
trouble
and correcting it
according to TROUBLE-
SHOOTING GUIDE .
. Turn off the power before
part removal or
mounting .
10
Fig . 11 Field
Thyrsitor Assembly
Field Thyristor Replacement
With all the Models, thyristor modules
consisting
of a thyristor
and a diode are used as the field
thyristor . Replace them as follows .
1 . Remove the
four mounting screws of field
snubber board (3PCB), lead
clamping screws,
control power
connector . Then, remove snubber
board . See
Fig . 11 .
2 . Remove lead clamping
screws connecting
to
thyristor, and
remove the leads from
thyristor .
In
this case, mark all terminals
for identification .
See Fig . 12 .
3 . Remove
thyristor mountingscrews
(2) and
remove thyristor module .
4 .
Check tY ;Ie type and capacity of
new thyristor
module against the
requirements . Install it by
reversing the removal procedure,
making con-
nections to the terminals
identified by the
marks
made before
removing the old thyristor
module .
Coat the thyristor mounting surface with joint
compound,
JOINTAL Z madeby Nippon Light
Metal Co . , Ltd .
Main Circuit Thyristor Replacement
VS-505W 1, 230 V at 25 A
The unit
uses a thyristor
module
consisting of
two
thyristors . Replace
it as follows
.
1 . Remove snubber
board (4PCB) mounting
screws (5) and lead clamping
screws . Remove
snubber board . (Fig
. 13)
2 .
Remove bus bar mounting screws
and lead
clamping screws
connected to thyristor . Remove
bus bar and leads . (Fig
. 14) In this case, mark
the terminals
for identification .
3
. Remove two
thyristor clamping screws and
thyristor .
4 . Check the
replacement module for type
and
capacity, and reinstall it by
reversing the dis-
assembly procedure,
identifying the terminals by
means
of the marks made prior to
disassembling .
THYRISTOR
MTGSCREWS
Fig . 12
With SnubberBoard Removed
Inspection
Part
Inspection
Item
Inspection
Procedure
What to do Remarks
Thyristor "
Noise " Check for Replace .
Rule of thumb
cooling any inter-
for cooling fan
fan
mittent or
replacement :
unusual
15,000 hours
noise . of
operation .
" Vibration " Feel by
hand . -
General " Dust or
. Check for
Clean with
dirt
dust clogging
an electri-
or
dirt
cal cleaner
" Loose
ter-
adhesion .,
Tighten .
minal
" Check
for
screws or
loose screws
nuts
or nuts .